Two monatomic ideal gases are in thermal equilibrium with each other. Gas A is composed of molecules with mass m while gas B is composed of molecules with mass 4m. The ratio of the average molecular kinetic energy KA / KB is

= 1

Explanation: Average molecular kinetic energy for monatomic idela gases is given by:

where

R is gas constant of ideal gas

T is temperature

Which means kinetic energy depnends only on temperature.

Since gas A and gas B are at the same temperature, kinetic energy will be the same. Therefore:

= 1

Ratio of this average molecular kinetic energy is 1.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.